More than two thirds of councils are failing to ensure enough childcare is provided for working parents, campaigners for families' rights have warned.
Just one in five local authorities have enough childcare for parents with children under two, and one in three for school age children, the Daycare Trust and Family and Parenting Institute said.
And just one in seven have enough childcare for disabled children - a figure which has not improved in five years, the charity said.
The research follows recently published Department for Work and Pensions figures that showed a third of parents who want to work more cannot because they are unable to find affordable childcare.
Daycare Trust and Family and Parenting Institute chief executive Anand Shukla said: "Councils across England and Wales are failing families by presiding over a continuing shortage of high quality, affordable childcare."
He added: "Local authorities have a legal duty to ensure a sufficient supply of childcare in their areas, but no doubt their failure to do so is linked to the tight financial squeeze they find themselves in, with ever more austere funding settlements.
The charity's Childcare Costs Survey 2013 also contains evidence suggesting that plans to increase the number of pre-school children that nurseries and childminders can look after will have little impact on childcare costs.
As part of coalition efforts to cut childcare costs, staff are to be able to take charge of six two-year-olds rather than four while the ratio for under-ones will go up from three to four.
A Government spokesman said: "We are reforming the childcare system so that providers have more flexibility when they have highly qualified staff and childminders are better supported. Ratio changes, which are not compulsory, will allow providers to have the flexibility to increase pay for better qualified workers."